fix: use global namespace when defining awslambda InvokeStore global type

[svozza]

Description of changes:

When using the new v0.2.0 version of InvokeStore I encountered the following error trying to use the global InvokeStore object:

globalThis.awslambda?.InvokeStore?.getContext()

The error:

src/LogAttributesStore.ts:92:31 - error TS2339: Property 'InvokeStore' does not exist on type 'typeof awslambda'.

92     if (globalThis.awslambda?.InvokeStore?.getContext() === undefined) {

The issue is because I am using the popular aws-lambda types package, which defines the awslambda global as a namespace:

declare global {
    namespace awslambda {
        class HttpResponseStream extends Writable {
            static from(
                writable: Writable,
                metadata: Record<string, unknown>,
            ): HttpResponseStream;
            setContentType: (contentType: string) => void;
        }
        function streamifyResponse<TEvent = any, TResult = void>(
            handler: StreamifyHandler<TEvent, TResult>,
        ): StreamifyHandler<TEvent, TResult>;
    }
}

As InvokeStore does not use a namespace, the global it defines does not get merged with the other awslambda namespace:

declare global {
    var awslambda: {
        InvokeStore?: InvokeStoreBase;
        [key: string]: unknown;
    };
}

I think the above may have been done this way to allow the InvokeStore field to be optional using the ? token. Namespaces don't support this but you can say a value can be undefined.

This PR makes the change to use a namespace instead. I have tested this with my project and the build error is resolved by this change.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[changeset-bot]

🦋 Changeset detected

Latest commit: a840984

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@aws/lambda-invoke-store	Patch

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[svozza]

So it turns out the issue here is not down to namespace merging but that when you only use the global instance of InvokeStore you need to add an empty import to the top of the file:

import '@aws/lambda-invoke-store';
 
export const handler = (event: unknown) => {
  globalThis.awslambda?.InvokeStore?.getContext()
  // ...
}; 

This only works if you are using v0.2.1 as the previous version did not export the types correctly for CommonJS. Closing this PR as not required.